This system replaces the analog speedometer and tachometer gauge cluster of a 750 cc Honda motorcycle with a computerized monitor system based on the INTEL 8085A microprocessor and family of peripherals. The system adds the enhanced functionality of engine temperature, battery charging, fuel level, turn signal, and kick stand monitoring and status display. A security function is also employed as a guard against unauthorized use or theft. The speedometer and tachometer functions utilize phototransistor sensors generating pulses derived from stock cable connections to the engine block and front wheel. The engine temperature, fuel level, and battery charging functions are implemented via A/D conversion of external sensor inputs. Turn signal and kick stand status functions are implemented by software polling of external switches. The system incorporates a small keyboard for input of a five digit security code. If the code input is correct, ignition is enabled and normal operation may follow. If the code input is incorrect, ignition is disabled, and the motorcycle horn is activated as an alarm. The operator is allowed two attempts at entrance of the five digit code. All system functions are displayed via various configurations of 7-segment and discrete LED displays for operator feedback. The system utilizes the twelve volt motorcycle power source and is contained on three double sided circuit boards. The system software was developed on the INTEL SDK85 system design prototype kit and transferred in final form to an on-board EPROM.
Library of Congress Subject Headings
Motorcycles--Design and construction--Data processing; Intel 8085 (Microprocessor); Intel SDK-85 (Microprocessor); System design
Department, Program, or Center
Computer Science (GCCIS)
Leet, Robert H., "An 8085 Microprocessor based monitor system for a 750 cc Honda motorcycle" (1988). Thesis. Rochester Institute of Technology. Accessed from
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